In a series and parallel combined electric vehicle (SPHV) disclosed in Patent Literature 1, its drive mode is switched to a series hybrid vehicle (SHV) mode or a parallel hybrid vehicle (PHV) mode. In the SHV mode, a generator is driven by a mechanical output of an internal combustion engine, and a motor is driven by electric power generated by the generator and discharged electric power from a battery, whereby wheels are driven by the motor. In the PHV mode, the wheels are driven by the mechanical output of the internal combustion engine. When the vehicle is started, accelerated or slowed through braking, a portion of a required driving force which cannot be achieved by the mechanical output of the internal combustion engine is complemented by the motor.
When the drive mode is shifted from the SHV mode to the PHV mode, the torque of the generator is controlled at a point in time when the vehicle speed (the rotational speed of the motor) reaches a predetermined value V1, so that the rotational speed of the generator gradually comes close to the rotational speed of the motor. Thereafter, the clutch is engaged at a point in time when the rotational speeds of both the generator and the motor coincide with each other and the vehicle speed reaches a predetermined value V2, so that the generator the generator and the motor are coupled together mechanically. In addition, when the rotational speed of the motor becomes lower than the predetermined value in the PHV mode, the generator and the motor are decoupled mechanically by releasing the clutch, whereby the drive mode is switched to the SHV mode.